With the widespread use of virtualization techniques, data centers or other facilities have been operating in a way such that resources of plural physical machines are managed in a centralized manner, and are treated as a shared resource pool. Further, with improvement in performance of virtualization, it has become possible that applications, which in the past had been difficult to be operated in virtual environments, can be operated in the virtual environments.
With techniques of moving virtual machines such as centralized management and live migration using the shared resource pool, it is possible to reduce the amount of electric power used in the system. This is because such a technique makes it possible to collect the virtual machines into a specific physical machine, thereby turning off the power supply consumed to the redundant servers. Further, by moving the virtual machines operating on the physical machine in the overloaded state to another physical machine, it is possible to prevent physical machines from being overloaded.
In the case where a certain virtual machine is moved to another physical machine, it is checked in advance to see if sufficient resources are available in the physical machine serving as the destination of movement. However, in an environment where physical machines having different performances coexist, there is a possibility that the amount of resource used by the virtual machine on a certain physical machine cannot be simply replaced with the amount of resource used on another physical machine. For example, if the clocks or the architecture of the central processing units (CPU) vary among the physical machines, the values of the percentages of CPU used differ from physical machine to physical machine.
In view of the facts described above, Patent Document 1 described below proposes a method in which the availability for processing performances in each of the physical servers is measured in the virtual server environments according to the same standard. More specifically, the method of Patent Document 1 below runs, on plural physical servers, performance-measuring virtual servers based on the same virtual server image including an operating system (OS) and a performance-measuring program, thereby collecting performance information measured by the performance-measuring virtual servers from each of the physical servers. With this method, it is possible to acquire the differences in availability of processing performance between physical servers according to the same standard on the basis of the difference of the collected performance information between the physical servers.